This belief is so much part of our culture that one often hears talk of a “mere” circumstantial case as contrasted to a solid case based on eyewitness testimony. In fact, research shows that eyewitness identifications are highly unreliable, especially where the witness and the perpetrator are of different races or when d when the identification occurs under the stress of a violent crime, an accident or catastrophic event.

2.Fingerprint evidence is foolproof. Not so. Identifying prints that are taken by police using fingerprinting equipment and proper technique may be a relatively simple process, but latent prints left in the field are often smudged and incomplete, and the identification process becomes more art than science. When tested by rigorous scientific methods, fingerprint examiners turn out to have a significant error rate.

3.Other types of forensic evidence are scientifically proven and therefore infallible.“[S]ubjective, pattern-based forensic techniques—like hair and bite-mark comparisons” leave much room for error. See Spencer S. Hsu, FBI Admits Flaws in Hair Analysis Over Decades, WASH. POST (Apr. 18, 2015), http://www.washingtonpost.com/local/crime/fbi-overstated-forensic-hair-matches-in-nearlyall-criminal-trials-for-decades/2015/04/18/39c8d8c6-e515-11e4-b510-962fcfabc310_story.html; Roger Koppl, CSI for Real: How to Improve Forensic Science, REASON FOUND., Dec. 2007, at 3-18 (detailing inadequacies in the practice of forensic science). Some fields of forensic expertise are built on nothing but guesswork and false common sense.21 Many defendants have been convicted and spent countless years in prison based on evidence by arson experts who were later shown to be little better than witch doctors. See Paul Bieber, Anatomy of a Wrongful Arson Conviction, THE ARSON PROJECT, http://thearsonproject. org/charm/wp-content/uploads/2014/08/wrongful_convictions.pdf (since 1989, 29 exonerations have involved arson convictions)

4.DNA evidence is infallible. This is true to a point. The integrity of the result depends on a variety of factors that are, unfortunately, not nearly so foolproof: the evidence must be gathered and preserved so as to avoid contamination; the testing itself must be conducted so that the two samples being compared do not contaminate each other; the examiner must be competent and honest. As numerous scandals involving DNA testing labs have shown, these conditions cannot be taken for granted, and DNA evidence is only as good as the weakest link in the chain. Paul C. Giannelli, Wrongful Convictions and Forensic Science: The Need to Regulate Crime Labs, 86 N.C. L. REV. 172-95 (2007).

5.Human memories are reliable.Science now tells us that this view of human memory is fundamentally flawed. The mind not only distorts and embellishes memories, but a variety of external factors can affect how memories are retrieved and described. In an early study by cognitive psychologist Elizabeth Loftus, people were shown videos of car accidents and then questioned about what they saw. The group asked how fast the cars were going when they “smashed” into each other estimated 6.5 mph faster than the group asked how fast the cars were going when they “hit” each other. A week later, almost a third of those who were asked about the “smash” recalled seeing broken glass, even though there was none. Elizabeth F. Loftus & John C. Palmer, Reconstruction of Automobile Destruction: An Example of the Interaction Between Language and Memory, 13 J. VERBAL LEARNING & VERBAL BEHAV. 585-89 (1974), available at https://webfiles.uci.edu/eloftus/LoftusPalmer74.pdf

6.Confessions are infallible because innocent people never confess.Innocent people do confess with surprising regularity. Harsh interrogation tactics, a variant of Stockholm syndrome, the desire to end the ordeal, emotional and financial exhaustion, family considerations and the youth or feeble-mindedness. One such instance took place in Lake County, Illinois, where local police interrogated Juan Rivera Jr. for 4 straight days until he suffered a psychological breakdown and confessed to sexually assaulting and killing a young girl. Rivera spent 20 years in prison until DNA evidence exonerated him in 2012. See Dan Hinkel, Wrongful Convictions: Exonerated Inmate Wins Early Round In Suit Against Lake County Officials, CHI. TRIB. (Oct. 14, 2013), http://articles.chicagotribune.com/2013-10-14/news/ct-met-juan-riveralawsuit-win-20131013_1_wrongful-convictions-dna-evidence-dna-exonerations; see also Brandon L. Garrett, The Substance of False Confessions, 62 STAN. L. REV. 1051, 1052-57 (2010); Jed S. Rakoff, Why Innocent People Plead Guilty, N.Y. REV. OF BOOKS (Nov. 20, 2014), http://www.nybooks.com/articles/ archives/2014/nov/20/why-innocent-people-plead-guilty/.

7.Juries follow instructionsWe have no convincing reason to believe that jury instructions in fact constrain jury behavior in all or even most cases. And, because the information we get from inside the jury room is so limited and sporadic, experience does little to improve our knowledge. Looking at 100 black boxes is no more informative than looking at one. Krulewitch v. United States, 336 U.S. 440, 453 (1949) (Jackson, J., concurring) (“The naive assumption that prejudicial effects can be overcome by instructions to the jury . . . , all practicing lawyers know to be unmitigated fiction.”).

8.Prosecutors play fair.The Supreme Court has told us in no uncertain terms that a prosecutor’s duty is to do justice, not merely to obtain a conviction. It has also laid down some specific rules about how prosecutors, and the people who work for them, must behave—principal among them that the prosecution turn over to the defense exculpatory evidence in the possession of the prosecution and the police.39 There is reason to doubt that prosecutors comply with these obligations fully. CENTER FOR PROSECUTOR INTEGRITY, AN EPIDEMIC OF PROSECUTOR MISCONDUCT, WHITE PAPER (Dec. 2013), available at http://www.prosecutorintegrity.org/wp-content/uploads/EpidemicofProsecutorMisconduct.pdf. Denis Slattery, Exclusive: Bronx Prosecutor Bashed and Barred from Courtroom for Misconduct, N.Y. DAILY NEWS (Apr. 4, 2014), http://www.nydailynews.com/new-york/bronx/bronxprosecutor-barred-courtroom-article-1.1746238 (noting that a Bronx prosecutor failed to present evidence that would have freed a man held at Rikers Island on bogus rape charges).

9.The prosecution is at a substantial disadvantage because it must prove its case beyond a reasonable doubt. Juries are routinely instructed that the defendant is presumed innocent and the prosecution must prove guilt beyond a reasonable doubt, but we don’t really know whether either of these instructions has an effect on the average juror. Nor do we know whether juries really draw a distinction between proof by a preponderance, proof by clear and convincing evidence and proof beyond a reasonable doubt. These levels of proof, which lawyers and judges assume to be hermetically sealed categories, may mean nothing at all in the jury room. My own experience as a juror certainly did nothing to convince me that my fellow jurors understood and appreciated the difference. The issue, rather, seemed to be quite simply: Am I convinced that the defendant is guilty? Norbert Schwarz et al., Metacognitive Experiences and the Intricacies of Setting People Straight: Implications for Debiasing and Public Information Campaigns, 39 ADVANCES IN EXPERIMENTAL SOC. PSYCHOL. 127, 152 (2007); Eliot G. Disner, Some Thoughts About Opening Statements: Another Opening, Another Show, PRAC. LITIGATOR, Jan. 2004, at 61 (“there is substantial evidence that juries normally make up their minds long before closing argument”

10.Police are objective in their investigations. In many ways, this is the bedrock assumption of our criminal justice process. Police investigators have vast discretion about what leads to pursue, which witnesses to interview, what forensic tests to conduct and countless other aspects of the investigation. Police also have a unique opportunity to manufacture or destroy evidence, influence witnesses, extract confessions and otherwise direct the investigation so as to stack the deck against people they believe should be convicted. And not just small-town police in Podunk or Timbuktu. Just the other day, “[t]he Justice Department and FBI [] formally acknowledged that nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all [of the 268] trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000.” Do they offer a class at Quantico called “Fudging Your Results To Get A Conviction” or “Lying On The Stand 101”? How can you trust the professionalism and objectivity of police anywhere after an admission like that? See The National Registry of Exonerations, Mark Prentice, https://www.law.umich.edu/special/exoneration/Pages/casedetail.aspx?caseid4540. In addition to the cases recorded by the National Registry of Exonerations, researchers became aware of more than 1,100 cases in which convictions were overturned due to just 13 police corruption scandals, the majority of which involved planting drugs or guns on innocent individuals. See Chris Seward, Researchers: More than 2,000 False Convictions in Past 23 Years, NBC NEWS (May 21, 2012), http://usnews.nbcnews.com/_news/ 2012/05/21/11756575-researchers-more-than-2000-false-convictions-in-past-23-years?lite; Sean Gardiner, Brooklyn District Attorney Kenneth Thompson Takes on Wrongful Convictions, WALL ST. J. (Aug. 8, 2014), http://www.wsj.com/articles/brooklyn-district-attorney-kenneth-thompson-takes-on-wrongfulconvictions-1407547937 (Brooklyn DA Kenneth Thompson’s conviction integrity unit has ordered the review of more than 100 prior convictions, 70 of which involved accusations that former Brooklyn Detective Louis Scarcella coerced confessions and tampered with witness statements); Spencer Ackerman, “I Sat In That Place for Three Days, Man”: Chicagoans Detail Abusive Confinement Inside Police “Black Site”, THE GUARDIAN (Feb. 27, 2015), http://www.theguardian.com/us-news/2015/feb/ 27/chicago-abusive-confinment-homan-square (four African-Americans describe being detained for several days inside a police warehouse, where they were “shackled and interrogated,” denied access to counsel and forbidden from notifying anyone of their whereabouts); see also Miriam S. Gohara, A Lie For a Lie: False Confessions and the Case for Reconsidering the Legality of Deceptive Interrogation Techniques, 33 FORDHAM URB. L.J. 791, 794-95 (2006); Laure Magid, Deceptive Police Interrogation Techniques: How Far is Too Far?, 99 MICH. L. REV. 1168, 1168 (2001).

Here is a study that documents how forensic analysts called by the prosecution provided invalid testimony at trial—that is, testimony with conclusions misstating empirical data or wholly unsupported by empirical data. This was not the testimony of a mere handful of analysts: this set of trials included invalid testimony by seventy-two forensic analysts called by the prosecution and employed by fifty-two laboratories, practices, or hospitals from twenty-five states. Unfortunately, the adversary system largely failed to police this invalid testimony. Defense counsel rarely cross-examined analysts concerning invalid testimony and rarely obtained experts of their own. In the few cases in which invalid forensic science was challenged, judges seldom provided relief. This evidence supports efforts to create scientific oversight mechanisms for reviewing forensic testimony and to develop clear scientific standards for report writing and testimony. The scientific community can promulgate standards to ensure the valid presentation of forensic science in criminal cases and thus the integrity and fairness of the criminal process. ﻿